Device for deflecting a high-speed jet of gas ejected through a nozzle



Nov. 23, 1954 E STAUFF 2,694,898

DEVICE FOR DEFLECTING A HIGH-SPEED JET OF GAS EJECTED THROUGH A NOZZLEFiled Aug. 3, 1949 3 Sheets-Sheet 1 Nov. 23, 1954 E. STAUFF 2,694,898

DEVICE FOR DEFLECTING A HIGH-SPEED JET 0F GAS EJECTED THROUGH A NOZZLEFiled Aug. 8, 1949 3 Sheets-Sheet 2 Fiq.5. Fig.6.

Nov. 23, 1954 E. STAUFF 2,694,898

DEVICE FOR DEFLECTING A HIGH-SPEED JET 0F GAS EJECTED THROUGH A NOZZLEFiled Aug. 8, 1949 5 Sheets-Sheet 5 IN VENTOR BY ya a L LO :FLOCESATTORNEY United States Patent DEVICE "FOR DEFLECTING..A- HIGH-SPEED JETOF .GAS EJECTEDTHROUGH A NOZZILE Emile, Stautr", Paris, :France,.assignor toThe French State, represented by the Ministere (16.1 18;Defense Nationale, Secretariat dEtat. 'aux...Forces. Armees. (Air),-.Paris, France Application August 8,1949, Serial No. 109,112 Claimspriority, application France August 9,1948

4 Claims. -(Cl. 60.-35.54)-:

The present inventionrelates to a particularly simple and economicaldevice Which 'is readily adaptable to any actuating member andwhich,owing to the rapidity with which it canchange its position due to-itssmall mass and its reduced movements, can housed-for progressivelydeviating a jet issuing from'the *nozzle of a jet motor with a view toproducing powerful'overall torques for the piloting of an aircraft, withthe minimum of power consumption and themaxirhum-of 'res'pon siveness,by the instantaneous alteration of the-,-pr'essure distribution alongthe wallis'of the. nozzle;

In order to varythedirection of a high-speed jet of gas, it is ingeneral necessary to exerta considerable force or to move considerablephysical masses. This fact is a drawback in certain applications suchas-. the use of a deflection of the propelling jet for producing "anartificial moment about the centre'of gravity of a jetpropelledaircraftyeither the necessary mechanism tegonliles complicated, orthe-consumption of power too The present invention relates to adeflecting-device that obviates the above-mentioned"drawbacks,since itenables considerable deflections, of" the orderofinagnitude of severalangular degrees, to be" effected in a "highspeed jet of gas while usingmovable parts of only small mass and-only'employingsmallforces'comparedto the result obtained The device according to the present invention isessentially characterized by the 'fact' that, it comprisesat least oneinterceptor which is made-to penetrate by means of a suitable actuatingsystem-into the-'stream'of gas, either through thewall o-f-the*nozzle,'or' behind szid nozzle, in order -tovary the direction of-"thejet gas.

Other features and the chief advantages of the invention: will becomeapparent from -the description thereof which will begivenhereinafter'with'-reference'-to the accompanying drawing whichillustrates diagrammatically and merely by way of example variousembodiments of the invention.

In said drawing:

Figs. 1a and lb show longitudinal sections of a nozzle provided with adevice according to the invention, for two different positions of theinterceptor.

Figs. 2a and 2b, respectively, show a longitudinal section and an endview of another embodiment of the invention.

Fig. 3 shows a system for actuating the interceptor.

Fig. 4 shows another embodiment of the invention.

Figs. 5 and 6 illustrate, respectively in longitudinal section and inend view, a device for controlling the interceptor.

Figs. 7 and 8 illustrate, respectively in longitudinal section and inend view, another embodiment of the contrcl device for the case wheretwo interceptors are pro- W e Fig. 9 illustrates diagrammatically theresultant forces where the interceptor is introduced at a small angle asheretofore proposed by others, and

Fig. 10 illustrates diagrammatically the resultant forces where theinterceptor is introduced at right angles within the supersonic jet asper the present invention. I

In the wall of a nozzle 1 an opening is provided through which isadapted to move an interceptor 2 of any suitable shape. The presence ofthis obstacle changes thedistribution of the pressure's: along thecorrespondin g wall of the nozzle, "thereby producing both atransverseforce applied .to said nozzle and :a deflection-of the jet issuingtherefrom. These two etfects are connected with one .another by the lawsof mechanics. Figs. 2 show a modification wherein ;the interceptor islocated outsidethe nozzle;

The high speed of the jetof-gas, which may be below or above the speedof sound, makes it :possibleto reduce considerably the response-lagofaerodynamic origin, as compared with similar control surfaces which aresubjccted only to-the wind-produ'ced-by the'flight-of'the aircraft;Furthermore, the action of the device obviously depends little on thespeed of :flight';

Another advantage of the-arrangementproposed is that, so long as nodefie'ction 'is required, the interceptor remains outside the jet "ofgas which may be at high temperature andbe moving at very high velocityconsequently; the interceptor-isless liable to damage than 'the knownsystem of deflecting flaps which are adapted to move about an axis atright angles to that 'offthe nozzle and 'arcconstantly immersed in thefluid stream.

The small-size. of the necessary =interceptors makes it:possible to'placea wholeseries2, 2a, 2b thereof in a ring about "a nozzle-ofrevolution *(see Fig. 4),

tionof the jet and for producing ;a discontinuous adjustmentof saiddirection according to the all-or-none principle.

In the case in which theinterceptor moves between two extreme positions,since ll 5 can only assume two values, -hi and-112* (see F-ig '3),this-movementmayadvantageouslybeobtained bysecuring the interceptor 2 tothe moving armature? of an electromagnet 4,10

whihcurrent-is supplied atywilljor automatically by means-of-a switch 5.In this casepthe. deflecting action,

"whichmay be very powerful, is, produced by actuating the switch 5; thecurrentconsumed by the electromagnet 4 may. be small'since the force-towhichthe interceptor is subjected in, the direction at right angles tothe axis'of the nozzle is almost zero.

Referring to Fig. 6,, the intercepting surface 2, which is-l'o'eated, inthis example, behindthe nozzle 1,. is integral with an arm-6 whiclrmayrotate about the shaft 7. This arm is normally maintained'in theretracted position of the interceptor, by means of a spring 8.

A lever 9 at the end of the shaft 7 is engaged by the rod 10 which isunitary with an iron member 11 adapted to be attracted by theelectromagnet 12.

When a current passes through the electromagnet 12, the iron member 11is attracted. The rod 10 pulls on the lever 9 and causes the shaft 7 torotate, the spring 8 to become extended and the interceptor 2 to beintroduced into the jet.

When the current ceases, the attractive force of the electromagnet onthe iron member is no longer exerted so that the interceptor is broughtback to its retracted position by the spring 8.

Figs. 7 and 8 show the case where two interceptors are provided. Theseinterceptors 2 and 2a are secured to the ends of a resilient blade 21secured to a member integral with the nozzle 1.

This resilient blade 21 carries an iron member 22 which can be attractedby the electromagnet 23.

The resilient blade returns into the jet the interceptor which haspreviously been retracted by the action of the electromagnet.

Both interceptors 2 and 2a are mechanically or electricallyco-ordinated. They move in the same direction, i. e. when interceptor 2is in the jet, interceptor 2a is outside the jet and vice-versa.

The device according to the invention may be used (a) For the pilotingof an aircraft, at any speed and at any altitude, either by a directaction of the pilot on the chosen interceptor surfaces by means ofconventional mechanisms or even by an indirect action by means of asuitable pulsating device (not shown);

(11) For deviating a gaseous jet issuing from a nozzle, whether thepurpose of this deviation be (or not) the protection of a space swept bythe jet or the feeding of a rotary power machine.

It is obvious that the invention has only been described and illustratedin a purely explanatory and in no wav limitative manner and that anymodification of detail may be made therein in accordance with itsprinciple without exceeding its scope.

It has been found by experience that in the case of a supersonic gaseousjet, the method of operation of an interceptor employed to produce acontrolling moment on a nozzle, as well as the results obtained aretotally different depending on whether the said interceptor isintroduced into the gaseous jet at a right angle or not.

According to established principles, an interceptor according to thepresent invention, introduced perpendicularly into a supersonic gaseousjet, gives rise to a separate shock wave inducing an over-pressure zoneupstream of the interceptor, the flow being subsonic within said zone.

An interceptor introduced, on the contrary, like standard aerodynamicfiaps, at a small angle within a supersonic gaseous jet gives rise to ashock-wave not detached from said interceptor, so that in that casethere is no over-pressure zone upstream of the interceptor, and the flowalong the latter is supersonic.

If follows from this essential difference, that:

(a) In the case where the interceptor 2 (see Fig. 9) is introduced at asmall angle inside the supersonic jet, the pressures acting upon saidinterceptor exert a force F1 giving rise to a diving moment, it beingnoted that the shockwave 01 not being separate and the flow along theinterceptor being as a result supersonic, considerable friction forcesF2 will occur and reduce the efficiency of the interceptor which thenonly operates through resultant R.

(b) On the contrary, in the case where the interceptor 2 (see Fig. 10)is introduced at right angles within the supersonic jet, the force F1acting upon the interceptor itself gives rise not to a diving moment butto a lifting moment (small in view of the short lever arm d1).

The diving moment results from the fact that the shock wave 02, which isseparate, gives rise to overpressures exerted along F, upstream of theinterceptor directly on the body of the nozzle.

The pressure and velocity changes within the gaseous jet caused byintroducing the interceptor 2 at a right angle are bound to each otherby the law of the quantity of motion.

The jet thrust that was axial before the introduction of the interceptorshows therefore a lateral component R, resultant of F and F1.

If R0 is the total thrust, the jet is accordingly deflected by an anglea such that sin R a R0 I claim:

1. In a device for deflecting a supersonic gaseous jet, a nozzle subjectto supersonic flow of a gaseous current therethrough, at least onemovable jet-intercepting surface disposed at right angles to the gaseouscurrent, said surface having relatively small dimensions in comparisonwith those of the nozzle and located adjacent the outlet orifice of thesaid nozzle and outside the nozzle when in the position of rest, the endof said intercepting surface adjacent said outlet orifice having a bevelshape so as to reduce frictional forces, and actuating means forintroducing a single movable interception surface at a time into thesupersonic gaseous current at right angles to said current, whereby thedisplacements of said movable surface result in an impact wave producingproportional changes in the distribution of pressure along thecorresponding wall of the nozzle upstream of the intercepting surfaceand a proportional substantial deviation of the longitudinal axis of thesupersonic jet without modifying the output of said nozzle.

2. In a device for deflecting a supersonic gaseous jet, a nozzle subjectto supersonic flow of a gaseous current therethrough, a movableinterceptor located immediately adjacent the outlet orifice of saidnozzle and having a deflecting surface disposed at right angles withrespect to the nozzle gas flow, and actuating means moving saidinterceptor into the supersonic gas stream in a direction perpendicularto the flow of gas to deflect the How of gas, producing an impact waveand thereby causing a substantial deviation in the direction of flow ofthe supersonic jet stream, said deviation of the supersonic jet streamresulting in a side thrust applied to the wall of the nozzle upstream ofthe interceptor.

3. Device according to claim 2, wherein the movable intercepting surfaceis located downstream relatively'to the outlet orifice of the nozzle.

4. Device according to claim 2, wherein the movable intercepting surfaceis located upstream relatively to outlet orifice of the nozzle.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,838,984 Berkowitz Dec. 29, 1931 1,879,187 Goddard Sept. 27,1932 2,077,471 Fink Apr. 20, 1937 2,395,809 Goddard Mar. 5, 1946 FOREIGNPATENTS Number Country Date 606,176 Great Britain Aug. 10, 1948

